Lithium phenyl 2 4 6 trimethylbenzoyl phosphinate lap

Gelatin methacrylate (GelMA, lyophilized, ∼60% methacryloyl substitution) and blue light source (3 W, 405 nm) were purchased from Suzhou Intelligent Manufacturing Research Institute (Suzhou, China). The photoinitiator (lithium phenyl-2,4,6 trimethylbenzoylphosphinate, LAP) was purchased from Tokyo Chemical Industry Co., LTD. (Tokyo, Japan). LAP solution was prepared by dissolving LAP powder in phosphate-buffered saline (PBS, Hangzhou Genom Biomedical Technology Co., Ltd., Hangzhou, China) and filter sterilized by Millex-GP syringe filter unit with a 0.22 μm pore size (Merck Millipore, Massachusetts, United States). The lyophilized GelMA was sterilized by UV for at least 30 min before being dissolved in the sterilized LAP solution. GelMA-LAP mixtures were stirred at 37 °C for obtaining uniform solution. The final concentrations of GelMA hydrogels were 5, 10, and 15% (w/v), respectively. The concentration of LAP was kept constant at 0.5% (w/v).
Matrigel (Corning No. 354277) was diluted to 100× with PBS and added to the surface of the GelMA hydrogel to submerge the GelMA matrix. The matrix is then incubated at 37 °C overnight. Afterward, the excess solution is aspirated, and the hydrogel is washed with culture medium to remove any unbound substances.

Lithium phenyl 2,4,6-trimethylbenzoyl
phosphinate (LAP) was purchased from TCI Chemicals. Bombyx mori cocoons were purchased from Evrosilk.
PCL (Purasorb PC12) was purchased from Corbion. Phosphate-buffered
saline (PBS) 1x (pH ∼ 7.4) was purchased from Sigma-Aldrich.
All other reagents and solvents were purchased from Sigma-Aldrich
and used without purification unless stated otherwise.

Guanosine
(G), 3-aminophenylboronic acid
hydrochloride (PBA) and gelatin (Gel) were purchased from Sigma-Aldrich.
Low-molecular-weight hyaluronic acid sodium salt (M_W = 80–100 kDa) and potassium chloride (KCl) were
purchased from Biosynth Carbosynth and ChemLab, respectively. The
4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride
(DMTMM) and lithium phenyl(2,4,6-trimethylbenzoyl)phosphinate (LAP)
were bought from TCI Chemicals and Carbosynth, respectively. The 2-(N-morpholino)ethanesulfonic acid buffer (MES, 0.1 M, pH
6.0) and Trizma buffer (68 mM, pH 7.4) were acquired from Alfa Aesar
and Sigma-Aldrich, respectively, and prepared in ultrapure water from
a Milli-Q Plus water purification system (resistivity > 18.2 MΩ·cm)
from Millipore. Unless otherwise specified, all chemicals were used
as received without further purification.

SilMA was prepared from silk fibroin from Bombyx mori according to the protocol reported in [23 (link)]; Hepcidin-25 and fluorescent hepcidin (hepfitc) were from Promega (UK); Lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) was from TCI Chemicals (US); Tris(hydroxymethyl)aminomethane (Tris base), morpholino-ethane sulfonate (MES), sodium dihydrogen phosphate, disodium mono-hydrogen phosphate, sodium chloride, Kalium chloride, human serum albumin, angiotensin, cytochrome c, and serum sample were from Merck Sigma Aldrich (Darmstadt, Germany). All reagents were of commercial grade and used as received.